1. Field of the Invention
This invention concerns surface profile measuring devices, and more particularly such devices which are suited to measuring surface roughness.
2. Description of the Prior Art
Measurement of surface roughness by noncontacting means has long been attempted by various optical methods involving light scattering, interferometers, lasers, etc. Problems of inadequate accuracy, undue complexity and incompatibility with current roughness standards (in that a direct profile readout typical of mechanical devices is not produced) have been encountered with many of these approaches. Examples of prior art approaches of this type are found in the following U.S. Pat. Nos: 2,315,282; 2,604,809; 2,693,735; 2,732,760; 2,755,702; 2,803,161; 3,019,347; 3,222,978; 3,286,582; 3,395,608; 3,509,349; 3,676,006; 3,794,427; and 3,796,495.
It is an object of the present invention to provide such an optical surface roughness measuring device for surfaces having a characteristic one directional surface lay which is relatively simple and produces a profile of the surface condition so as to be compatible with current surface roughness standards.